Automatic cam grinding machine



May 17, 1938.

H. A. SILVEN ET AL AUTOMATIC CAM GRINDING MACHINE Filed Dec. 26, 1935 6 Sheets-Sheet l m E m V M w M G HIWMMWU 5 LIN E.. @mw .www www w www w E m .TS www R G L han. .n "hwk MQNNN mmh. M M w H C 1115 www whwh w: .J N bmw Uf.. u w w nwww Q N. m E h. mi www www wwmvww Bw www www w www. Rw iw A f n sw www .m m m J .TQM www www f (f www w wwwmw www .n mhwwhw n m |U` www www Ew www *Ww s .u .o nQNN 1 l 9 N E www `ww Rww. w A .www L m .NAN DNN m`N MHTN .VMM NNNQNN w .BNN .VN m bmw www www S May 17, 1938. H. A. slLvEN x-:r Al.

AUTOMATIC CAM GRINDING MACHINE Filed Dec. 26, 1935 6 Sheets-Sheet 2 N 3mm/D014. HERBERT/4. SlLvE/v EARL G'. H YGARE @3% M Ll) www Wd W May 17, 1938. H. A. slm/EN ET AL 2,117,916

AUTOMATIC CAM GRINDING MACHINE Filed Dec. 26, 1935 6 Sheets-Sheet 3 T Zl/ QL/.63." 2,

HERBERT/. SlLvE/v @TNI-56s -C'ARL G FLYGARE H. A. slLvEN ET A1. 2,117,916

AUTOMATIC CAM GRINDING MIACHIVNE Filed Dec. 26, 1935 6 Sheets-Sheet 4 May 17, 1938.

v fl/U 255 257 me/MM@ HERBERT/4. 5' 11. VEN CARL G. FLYGARE May 17, 1938.

H. A. sxLIVEN ET A1.

AUTOMATIC CAM GRINDING MACHINE e sheets-sheet 5 5 Filed Deo. 26, 1935 HERBERT/. SILVEN CARL G'. FLYGARE ummm,

6 Sheets-Sheet 6 H. A. SILVEN El' AL AUTOMATIC CAM GRINDING MACHINE Filed Dec. 26, 1955 IIIIIL HERBERT/l. SIU/EN CARL G'. FLYGARE May 17, 1938.

Patented May 17, 193% ainsi PATENT ,oFF-ICE AUTOMATIC CAM GRINDING MACHINE I Herbert A. Silven and Carl G. Flygare, Worcester, Mass., Worcester, Mass., setts Application December 26, 1935, Serial 14 Claims.

This invention relates to grinding machines, and more particularly to an automatic camshaft .grinding machine.

One of the objects of this invention is to provide a simple and thoroughly practical machine for automatically grinding a plurality of cam blanks on an integral camshaft. A further objectl of this invention is to provide an automatic cycle controlling mechanism for controlling the feeding movement of the grinding wheel, the positioning movement of the work table, and the rocking movement of the cam toward and from the grinding wheel to grind successive cams automatically to a predetermined size and contour.

Another object of this invention is to provide an automatic cycle controlling mechanism in which a cycle controlling valve is actuated after the cam being ground has rotated a predetermined number of rotations in contact with the grinding wheel. A further object is to provide an electricallyY controlled hydraulic mechanism for controlling a cycle control valve which in turn controls the admission of fluid to the wheel feed cylinder, the table positioning cylinder and the rock bar cylinder.

A. further object of this invention is to provide a counting mechanism which operates after a predetermined number of rotations of the work n to actuate a cycle pilot valve to shift a main control valve to control the cycle of operation of the machine. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements vof parts, as will be exemplified in the structure to be hereinafter described, and the scope ofthe application of which will be indicated in the following claims.

In the accompanying drawings, in which is shown one of the possible embodiments of the mechanical features of this invention,

Fig. 1 is a front elevation of a grinding machine embodying this invention;

Fig. 2 is a diagrammatic view showing the piping diagram and the electrical control circuit;

Fig. 3 -is a fragmentary left end view of the grinding machine shown in Fig. 1, having parts broken away and shown in section to more clearly show the construction; 'V

Fig. 4 is a fragmentary front elevation -of the control mechanismv shown in Fig. 3;

Fig. 5 is a vertical sectional view, taken approxiimately on the line 5-5 of Fig. 3, showing the details of the counting mechanism and the nose' lifting device;

asslgnors to Norton Company,

a 'corporation of Massachu- Fig. 6'is a fragmentary sectional view, on an enlarged scale, showing the cycle pilot valve and its actuating solenoid;

Fig. 7 is a fragmentary sectional view, on an enlarged scale, of the right end of the cycle pilot 5 valve shown in Fig. 6;

Fig. 8 is a fragmentary view, on an enlarged scale, of the main control lever for starting the cycle of operation; p

Fig. 9 is a fragmentary perspective view, on. an 1o enlarged scale, showing the details of the lever controlling mechanism;

Fig. 10 is a fragmentary view, on an enlarged scale, of the control lever mechanism when the work is at its extreme right-hand position;

Fig. 11 is a fragmentary sectional view ,taken approximately on the line II--II of Fig. 4; and

Fig. 12 is an enlarged right-hand end elevation of the cycle control mechanism with the cover removed.

A cam grinding machine has been illustrated in the drawings having a base I0 which supports `a longitudinally movable work table II on the usual fiat way I2 and V-way I3. The base I@ also supports a transversely movable wheel slide I5 on ways (not shown) for a transverse feed-` ing movement toward and from the work; sup porting table II. The wheel slide I5 supports a rotatable grinding wheel I5.

The longitudinally movable work table Ii sup- 30. ports a pivotally mounted rock bar I8 which is supported in bearings I9 and 20 on the table Ii (Figs. 1 and 3) and is arranged so that it may be rocked about an axis which is substantially parallel to the axis of the grinding wheel I6. The rock bar I8 is provided with a rotatable headstock spindle 22 and a headstock center 23. 'I'he rock bar valso supports a footstock 24 having a footstock center 25. The headstock center 23 and footstock center 25 are. arranged to rotatably 40 support a camshaft 26 to be ground.

Master cams and roller In order that the cams on the camshaft 26 may be ground to a predetermined size and contour, it is desirable to provide a series of master cams for controlling the rocking movement of the rock. bar lI8 'so as to rock the cam being ground toward and from the wheel periphery to .generate a predetermined shape thereon. The

headstock spindle 22 is provided with a plurality of Amaster cams 28 which are mounted on the headstock spindle which is in axial alignment with the axis of the camshaft 26 being ground. A master cam roller or ,follower 29 is slidably 55 mounted on a rotatable shaft 38 which is rotatably supported in brackets 3| and' 32 (Figs. `1 and 3). The master cam roller 29 is preferably indexed automatically as the table II is moved longitudinally to position the master cam roller 29 opposite the master cam 28 which corresponds to the cam being ground on the camshaft 26. A slidably mounted yoked member 34 straddles the master cam roller 29 and is connected to a slidable rack bar 35 which meshes with a gear 36. The gear 36 is rotatably supported on one end of a rotatable shaft 31 which is preferably rotated by a train of gears by means of a star wheel and dog bar (not shown) the latter of which is fixed to the base of the machine. The details of the master cam roller indexing mechanism have not been completely illustrated since this feature is not considered part of the present invention. For a detailed disclosure of the automatic shifting of the master cam roller, reference may be had to the prior United States Patent No. 1,783,755 to Trefethen and Belden and also to the United States Patent No. 2,022,178 to Belden and Silven dated November 26, 1935.

Table traverse The work supporting table II is moved longitudinally relative to the base I8 by means of a fluid pressure operated mechanism comprising a cylinder 39 which is fixed to the base I 0. A piston 40 is slidably mounted within the cylinder 39 and is connected by means of a piston rod 4I with a bracket 42 depending from the table II. Fluid under pressure may be admitted either through a pipe 43 into a cylinder chamber 44 to cause the piston 40 and the table II to move toward the right, as viewed in Fig. 2, or it may be admitted through a pipe 45 into a. cylinder chamber 46 to cause the piston 48 and the work supporting table I I to move toward the left, as viewed in Fig. 2. The admission of fluid to the cylinder 39 is controlled by a valve mechanism to be hereinafter described.

Wheel feed The wheel slide I5 may be moved transversely on the base I8 by a feeding mechanism which may be actuated either manually or hydraulically, as desired. In the preferred construction, the Wheel slide I5 is provided with a depending nut 58 which meshes with a rotatable feed screw 5I which is preferably connected so that it may be rotated by a manually operable feed wheel 52 on'the front of the machine base I0. The feed screw 5I is arranged so that it may be moved bodily in an endwise direction to rapidly move the grinding Wheel slide I5 and the grinding wheel I6 either toward or away from the work. This is preferably accomplished by providing the feed screw 5I with a rearwardly extending piston rod 53 which carries a piston 54 slidably mounted within a cylinder 55.

The fluid pressure system may be supplemented by a hydraulically operated dash pot feed control (not shown). This dash pot mechanism may be arranged as shown in the patent to Silven No. 2,023,704 dated December 10, 1935. 'Ihe dash pot feed control mechanism has not been illustrated in the present application, since this feature is not considered a part of the present invention. For further details of this dash pot construction, reference may be had to the above-mentioned patent. By utilizing a dash pot mechanism of this type, the wheel may be advanced rapidly by admitting uid under pressure through a pipe 56 into a cylinder chamber 51 to move the wheel slide rapidly up to a position where the wheel is about to contact with the cam to be ground. Then the dash pot piston is picked up by the piston rod 53 and the further advance of the grinding wheel in grinding the camshaft is controlled by the exhaust of fluid from the dash pot cylinder. In order to remove the grinding wheel from contact with the work after the cam being ground has been ground to a predetermined size and contour, the admission of fluid under pressure to cylinder 55 is reversed and fluid is admitted through a pipe 58 into a cylinder chamber 59. A reversing valve 68 is provided to control the admission of fluid to the cylinder 55. In the position of the parts as shown in the diagrammatic view in Fig. 2, fluid under pressure from a tank or sump 6I within the base I8 passes through a pipe 62 and is forced under pressure by a iluid pump 63 through a pipe 64 into a valve chamber 65 between the valve pistons 66 and 61. In the position of the valve 60, as shown in Fig. 2, uid under pressure entering the valve chamber 65 passes outwardly through the pipe 58 and into the cylinder chamber 59 to cause the piston 54 to move rearwardly or toward the right, as viewed in Fig. 2, to withdraw the grinding wheel from engagement with the work.

, During the rearward movement of the piston 54, fluid exhausts from the cylinder chamber 51, through the pipe 56, through a V-port 68, into a valve chamber 69, between the yalve piston 10 and the valve piston 66, and through a passage 1I and exhausts through a pipe 12 into the reservoir 6I. When it is desired to cause an approaching movement of the grinding wheel I6, the valve 60 is shifted so that fluid under pressure passing through pipe 64 enters the cylinder chamber 65 and passes out through V-port 68 and pipe 56 into cylinder chamber 51 to cause the piston 54 to move toward the left, as viewed in Fig. 2, and thereby cause the grinding wheel I6 to be moved transversely toward the work piece to be ground. During the forward feeding movement of the grinding wheel, iiuid is exhausted from the cylinder chamber 59, through pipe 58, and passes out through a V-port into a valve chamber 15 between the valve piston 61 and a valve piston 16, and through passage 1I and exhaust pipe 12, into the reservoir 6I.

Spring actuation rock bar In order that the master cams may be maintained in operative engagement with the master cam roller during the grinding operation on,a cam, a yieldable pressure device is provided which serves to yieldably maintain the master cam in Contact with the follower roller. As shown in the drawings, the rock bar I8 is provided with an arm 11. A cylinder 18 is fixed to the bracket 3I pivotallyby means of a circular clamping band 19. 'I'he cylinder 18 contains a piston 80 which is connected by a piston rod 8I with a stud 82 on the arm 11. A spring 83 surrounds the piston rod 6I and is contained within the cylinder 18 between the piston and a head 84 xed in the lower end of the cylinder 18. 'I'he compression of the'spring 83 is of suflicient strength to maintain the master cam 28 in operative contact with the master cam roller 29 during the grinding operation. This mechanism is substantially identical with the construction shown in the United States patent to Belden and Silven No. 2,022,178 dated November 26, 1935.

Hydraulic actuation rock bar A pressure is admitted through a pipe 89 into a iii) cylinder chamber 90 within the cylinder 85, the piston 86 moves downwardly and contacts the screw 88 and the arm 11 to rock the bar I8 and separate the master cam 28 from the follower roller 29. A valve in the pipe 89 may be regulated to control the downward movement of piston 88 to avoid any possible jolt with too rapid movement.

Grinding wheel drive mechanism The grinding wheel may be driven from any suitable source of power, such as a driving motor (not shown) mounted either on the base ofthe machine or on the floor adjacent to the machine, as shown in the prior Patent No. 2,022,178, to which reference may be had for a disclosure of the wheel driving mechanism. This feature is not considered a part of the present invention and consequently has not been illustrated in detail.

Table traverse or indexing movement The work table II is traversed or indexed longitudinally and automatically by means of a fluid pressure system above described which comprises the cylinder 39 containing a piston 40 which is connected by the connecting rod 4I with the depending bracket 42 on the table II. The admission of Huid to either cylinder chamber 44 or i9 is controlled by a table reversing valve 9|. Fluid from the pump 63 passes through a pipe 9i, through a pipe 93, into a valve chamber 94 between valve pistons 95 and 96. A pipe 45 is connected between the valve 9I and the cylinder chamber 46 and a pipe 43 is connected between 'the valve 9I and the cylinder chamber 44. It will be readily apparent from this disclosure that when the table reversing valve 9I is in the position illustrated in Fig. 2, no fluid is admitted to either of the cylinder chambers and the table will remain stationary. The valve 9i is provided with a valve stem 91 which is operatively connected to a manually operable control lever 98 mounted on a rock shaft 99 by means of a short arm |00. The arm I is mounted on the rear end of the shaft 99 and has a pin I0| engaging a spool I02 on the valve stem 91. It will be readily apparent from this construction that when the lever 98 is moved in a clockwise direction, the valve stem 9 1 will be moved toward the left, as viewed in Fig. 2, so as to admit uid through the pipe 43,.to the cylinder chamber d4, and cause a movement of the table II toward the right (Figs. 1 and 2). Similarly, when the lever 98 is moved in a counterclockwise direction, the valve stem 91 will be moved toward the right (Fig. 2) so as to pass fluid through the pipe 45, into the cylinder chamber 46, to move the table II toward the left (Figs. 1 and 2).

The lever 98 is normally held in a broken line position 98a or 98hby means of an arrow point i105 on the lever |00 fixed on the end of shaft 99 and is engaged by a spring pressed roller i08. The lever is in the broken line position 98a, while the table is indexed intermittently in a direction towardthe right. The lever 98 is in a broken line position 90b, as indicated in Figs. 4 and 10, while the table is being traversed toward the left.. The valve stem 91 is normally held in a position to admit fluid through the pipe 93 or the pipe 49 to the cylinder 99. The admission of fluid through the pipe '93, to the valve 9I, lscontrolled by a main control valve, as will be described hereinafter.

An actuating mechanism is provided for the valve so that movement of the work supporting table II operates to close the valve 9i so that when the table is traversed a predetermined `distance to position the next cam in front of the grinding wheel, the valve is automatically closed to stopthe table movement. This is preferably accomplished bymeans of a dog bar H0 which vis adjustably mounted on the front edge of the table II by means of bolts in elongated slots.

The dog bar H0 is provided with a T-slot III which serves to support and guide a plurality of, adjustable dogs Iii. The dogs may be adjusted along the bar H0 to conform with the spacing of the cams on the camshait to be ground. The dog bar, ii necessary, for any variation in successive camshaits, may be adjusted longitudinally of the table without upsetting the adjustment of the individual dogs. In order that the control lever 99 may move in the direction of movement of the table, it is necessary to -provide a secondary actuating lever for cooperating with the table dogs. As illustrated in the drawings, a dog lever H4 is pivotally mounted on a stud II5. The lower end of the dog lever II4 is provided with a projecting pin H9 which rides in a cylindrical aperture I I1 in the lever 98.

Assuming the lever 98 is positioned as shown in Fig, 4, that is in a neutral position for starting of the grinding cycle, with the dog lever H4 in contact with table stop dog II3 which is adjustably mounted on the table II, the lever 98 is thrown either manually or automatically into a position viiiio. to move the valve stem 91 and admit fluid Athrough pipe i3 into cylinder chamber M to start the movement of the table in a direction toward the right, as viewed in Figs. 2, 4, and 9. This movement traverses the left, with a stop screw lill, both of which are carried by the lever 98. This action swings the lever 98 from the position 98a. into the full line position 99, as illustrated in Fig. 4, with the arrow point W5 depressing the spring pressed roller I06. The parts, however', are adjusted so that the arrow point does not reach the high point on the yspring roller, so that the roller is at all times exerting a pressure tending to move the lever 99 either in a clockwise or counterclockwise direction. The swinging of the lever 98 from the position 98a into the i'ull iinc position, as indicated in Fig. 4, moves the valve stern 91 into the4 position, as illustrated in Fig. 2, cutting oil? fluid under pressure from both of the pipes 43 and 45, thereby stopping the movement of the work carrying table II. By adjust'- ing the position of the dogs H2 along the dog bar IIO, the stopping position of the table may be adjusted, as desired, so that the product cams will be positioned successively in operative relation with the grinding wheel.

The dog lever H4 is slidably mounted on the stud ||5 so that it may be thrown out of the path of the dogs ||2 to permit a further traversing movement ofthe table. A lever 20 is pivoted on a stud |2| and at its upper end is formed as a yoke having pins |22 and |23 engaging slots-in opposite sides of a hub |24 of the lever ||4. When the lever |20 is moved from the full line position, as indicated in Figs. 2 and 11, and rocked in a clockwise direction, as' shown in Fig. 11, the dog lever 4 is moved rearwardly or toward the right, as shown in Fig. 11, on the stud ||5, out of the path of the dogs ||2, so as to permit a further traversing or indexing movement of the table. A spring |25 maintains dog lever ||4 in alignment with dogs ||2 during the indexing traverse of table This movement is preferably accomplished in timed relationship with the other operating mechanisms of the machine. A fluid pressure cylinder |21 is mounted within the machine base and is provided with a piston |28 having a piston rod |29 engaging an end |30 of the lever |20. A spring 4lill which surrounds the piston rod |29 serves to normally retain the piston in its rearward position. Fluid under pressure is admitted through a pipe |32 into a cylinder chamber |33 in timed relationship with the other operating mechanisms of the machine, to rock the lever |20 in a clockwise direction (Fig. 11) and thereby slide the dog 'lever ||4 into an inoperative position out of alignment with the dogs |2. This mechanism is preferably connected to a main control valve, which is hereinafter described, so as to operate automatically in timed relation with the other movements of the machine.

Pilot 'valve After the work table has been indexed intermittently for grinding successive cams on a camshaft, it is then desirable to shift the traverse table index control valve 9| into a reverse position so that the arrow point |05 rides on the opposite Y an adjustable truing dog |31 mounted on table (Figs. 4 and 9)` engages theupper end of a vpilot valve lever |38 and rocks it so as to move a valve stem |39 toward the right, as viewed in Figs. 2 and 4, so as to admit fluid which enters through a pipe |40 and a valve chamber |4| into a pipe |42 which passes fluid under pressure into a valve chamber |43 at one end of the table reversing valve 9|. 'I'his pressure moves the valve stem 91 so that the control lever 98 and the arrow point |05 pass over the high point on the spring pressed roller |06 and shift the valve 9| into a reverse position so that after truing of the grinding wheel, the table is ready for an intermittent traversing or indexing movement in a direction toward the right, as viewed in Figs. 1, 2 and 4.

' Wheel truing mechanism In a machine of this type, it is desirable that the grinding wheel be automatically trued in between operations so that a freshly trued grinding wheel vface may be presented at the start of each grinding operation A truing apparatus comprising a bracket |45 is fixedly mounted on the table and carries a truing tool |41 (Fig. 3) which may be adjusted by means of a micrometer mechanism |46. The details of the truing mechanism have not been illustrated in detail since this feature is not considered a part of the present invention. For further details as to this mechanism, reference maybe had to the U. S. patent to Belden and Silven No. 2,022,178 dated November 26, 1935. After the last cam on the shaft has been ground, the grinding wheel is moved to an extreme rearward position with the piston 54 engaging the rear end of the cylinder 55 (Fig. 2). The table is then given an additional traversing movement to carry the previously adjusted diamond or truing tool across the operative face of the grinding wheel I6, while it isin its extreme rearward position.

The normal traversing or indexing movement of the table is comparatively rapid to prevent loss of time between successive grinding operations. The normal table speed is not at all suited for a truing operation which requires a very slow; uniform relative traversing movement between the truing tool and the grinding wheel. To obtain a slow traversing movement of the table, a suit- Aable slow feed or throttle valve |50 is provided.

When fluid is exhausted from the cylinder 39 through either pipe 43 or 45, it passes through either a valve chamber 5| or |52, pipes |53 or |54 respectively, and then through a valve chamber |55 or |56 in the pilotvalve |35 and through a common exhaust pipe |51 which enters a valve chamber |58 in the slow speed valve |50. A V- port |59 in the valve chamber |58 is connected by a pipe |60 with the reservoir 6|. During the normal traversing or indexing movement of the table, the V-port |59 is wide open, permitting unrestrained exhaust of fluid from the cylinder '39. When the table indexes or traverses from the last cam on the camshaft and moves toward a truing position, a depending cam surface |62 on truing dog |31 strikes a roller |63 which is mounted on the upper end of a spring-pressed plunger |64. The lowerend of the plunger engages a rock arm |65 mounted on the outer end of a rock shaft |66. The other end of the shaft |66 carries a rock arm |61 which is connected by a pin |68 to move a valve stem |69 of the slow speed valve |50. When the cam surface |62 moves the roller |63 downwardly, it rocks the shaft |66 and arm |61, and the valve stem |69 moves a valve piston toward the right, as viewed in Fig. 2, to partially close the V-port |59, thereby restricting the exhaust of uid from the table traversing cylinder 39 so as to produce a slow traversing movement of the work table and the diamond or truing tool across the operative face of the grinding Wheel I6.

At the same time, the slow speed valve moves to throttle the exhaust of uid to cause a slow truing movement of the table. A pipe |1| is uncovered by movement of a valve piston |12 to admit fluid under pressure from a pipe |85 through a valve chamber |13 to the pipe |1|, into a cylinder chamber |9| to actuate a lever |92 and thereby stop the wheel spindle reciprocation during the truing movement. The table continues its truing movement toward the left, until the pilot valve lever |38 engages a depending projection on an adjustable truing dog |31 to move the pilot valve |35 from a neutral position and admit fluid under pressure into the valve chamber |43 of the table traverse valve 9| to armere reverse the direction of travel of the table. The table also moves slowly to pass the diamond across the face of the wheel on its return stroke. The slow movement continues until the roller |63 rides up the cam surface |62 on the dog |31 as the table approaches the first cam on the shaft into position for starting the next grinding cycle.

A spring |91 connected between the lever |81 and a stud |98 on the valve |50 serves to return the valve stem |69 toits normal position so as to uncover the pipe |1| tol allow fluid to exhaust from the cylinder chamber |3|, through the pipe |1|, a valve chamber |99, a pipe 200, and a pipe 20|, into the reservoir 0I, thus allowing the spring 202 to swing the lever v| 92 to start the wheel spindle reciprocation ready for the grinding of the next camshaft. At the same time, the V- port |69 is uncovered and unrestricted exhaust of fluid from the tabletravexse cylinder 33 starts the table il at its normal traversing or indexing speed.

While the apparatus shown is set to pass the diamond across the face of the wheel once in each direction, it is possible to adjust the truing dog B31 so tirata cam actuated star wheel will provide a greater number of passes of the diamond across the operative face of the grinding wheel, if desired. The details of construction of the truing dog have not been illustrated in the present case, since this feature is not considered a part of the present invention. Reference may be had to the prior United States patent to Belden and Silven No. 2,022,178 dated November 26, 1935 for details of disclosure of the truing dog.

Main control valve In a machine of this type, the mechanisms function automatically to successively grind a plurality of cam blanks ona camshaft to a predetermined size and coniour; and it is essential that al1 of the mechanismsfbe properly timed. Inasmuch as most of the mechanisms .of the machine are controlled by fluid pressure mechanisms, it is desirable to provide a main control valve |15 which is so contructed as to admit fluid under pressure successively tothe various mechanisms of the machine to.- produce the desired cycle of operation. As illustrated in the drawings, the main control valve |15-having a valve stem |14 is arranged to control lthe movement of the hollow valve member having valve pistons |16, |11, |13, |19, |30, |8|, and |82. Fluid under pressure from the pump 93 passes through the pipe 92, into a valve chamber |03 in the main control valve |15. From this-valve chamber, iiuid under pressure passes through a pipe |85 to the slow speed or throttle valve |50. Fluid under pressure from the valve chamber |83 also passes through a central aperture |88 extending longitudinally within the main control valve. Fluid from the passage |86 enters a valve chamber |81 and passes out through the pipe 93 into the valve chamber 94 ofthe traverse or table index controlvalve 9|. At the same time, fluid under pressure passing through the central aperture |86 passes into a valve chamber |08 and out through a pipe |89 into a valve chamber |90 in the wheel feed control valve 60. Fluid under pressure entering the valve chamber |90 serves to move the feed control valve 60 in a direction toward the right (Fig. 2) to uncover the pipe 58 so as to cause a rearward feeding movement of the grinding wheel i6. y 4

The main control valve stem |14 is provided a rock shaft 2W. The' upper end of the lever with a spool shaped member 205 which is connected by a stud 206 carried by a lever 201 pivotally mounted on a rock shaft 208. The lever 2015is provided with a stud 200 which is connected to one end of a spring 2|0, the other end of which is fastened to a stud 2li. The spring 2|0 tends to move the valve piston of the main control valve |15 toward the right, as viewed in Fig. 2. The upper end of the lever 201 is pro'- vided with a notch 2|2 within which a pin 2|3 rides. The pin 2|3 is mounted on the inner end of a link. 2M. The forward end of the link 2M is provided with a spool shaped member 2|5 which is arranged to be engaged by a yoked end 2|6 of a lever 2|1 which is pivotally mounted on 2|1 is provided with a projection 2|9 which is arranged toy drop into any one .of a plurality of notches 220 in the bar 22| which are spaced so that the projection 2|9 is aligned with a notch on the bar 22| only when a cam to be ground lis in operative position ywith relation to the grinding wheel. During the traversing movement of the table the projection 2|9 of the lever 2I1 is prevented from dropping into the notches 220 by the surfaces 222 on the bar 22|. These surfaces prevent the main control valve from being shifted to cause an infeeding movement of the grinding wheel except when the cam to be ground is opposite the grinding wheel.

Cycle pilot lvalve In order that the main control valve4 |15 may be shifted to control the cycle of operation as desired, a cycle pilot valve 225 is provided. This valve is of the piston type having valve pistons 226, 221,228, and 229. Fluid under pressure passing through the pipe 92 passes through a pipe 230 into pilot control valve chamber 23| and, in the position illustrated in Fig. 2, passes out through'a pipe 232, into a chamber 233 at the right end of the main control valve |15 and serves to move the main control valve |15 into the position illustrated in Fig. 2. A spring 234I serves to normally hold the pilot valve stem 235 to the right, as illustrated in Fig. 6, so that fluid under pressure enters the pilot valve chamber 23| andpasses through pipe 232 into chamber 233 to normally hold the main control valve in the position illustratedin Fig. 2. When the main control valve is moved into the position illustrated by fluid passing through the cycle pilot valve, fluid is exhausted from a chamber 236 at the left-hand end of the valve |15, forcing fluid out through a pipe 231 through a valve chamber 238 in the cycle pilot valve through a V-port 326 and out through a pipe 239 which returns the fluid to the reservoir 6|. A similar V-port 321 is provided to control the exhaust of fluid from the pipe 232 when the cycle pilot valve 325 is in the upward position (Fig. 2). An adjustable stop 323 is provided to limit the movement of the valve toward the right (Figs. 6 and 7). By adjusting the posiiton of the stop 328, the aperture of the V-port 321 may-be varied as desired. The spring 234 serves to retard the movement of the valve toward the left (Figs. 6 and '1) so that fluid exhausting through the pipe 231 may have ample time to pass outI through V-port 326 and through pipe 239 into the reservoi'r.

A solenoid 240 is connected to the upper end of the valve stem 235, ,as illustrated in Fig. 2, and serves when energized to shift' the cycle pilot valve into the dotted line position, as indicated in Fig. 6. In this position of the valve pistons, fluid under pressure from the pipe 230 entering the Valve chamber 23| passes through pipe 231 into valve chamber 236 in the end of the main control valve |15 to move the main control valve stem 14 toward the right, as viewed in Fig. 2f 'Ihis movement of the control valve serves to admit fluid under pressure to the'various mechanisms of the machine. 'Ihe solenoid 240 is preferably connected in a manner to be hereinafter described, to control the movement of the cycle pilot valve which in turn controls the admission of fluid to shift the main control valve |15 at a predetermined time in the grinding cycle.

When the solenoid 240 functions to pull the valve pistons of cycle pilot valve 225 into the dotted line position, Fig. 6, the spring 234 is compressed, serving to slow down the shifting of the valve pistons to allow time for fluid to exhaust from chamber 233 and the valve stem |14 of the main control valve |15 to be near its extreme right-hand position, Fig. 2, before valve piston 223 reduces the V-port exhaust 4through pipe 239 to cushion the movement of valve stem I 14 to its extreme right-hand position.

Similarly, when the solenoid 240 is released, the released compression of the spring 234 returns the cycle pilot valve 225 to the position indicated in full lines, Figs. 2 and 6. In order to retard the return movement of cycleA pilot valve 225 to obtain smooth operation of the hydraulic unitsfa stationary dash pot plunger 24| having a reduced portion is slidably mounted with a cylinder and is arranged to force fluid from the cylinder through ports 2,42 into chamber 23|. 'I'his serves to slow down the return of the valve stem 235 to the full line position, Fig. 6. Exhaust of fluid through ports 242 resultsin a quicker movement of valve stem |14 to the left, Fig. 2, before valve piston 226 reduces the V-port exhaust through pipe 239 from chamber 236 to cushion the movement of valve stem |14 to its extreme lefthand position, Fig. 2.

'I'he position of valve stem 235 in either direction to cut oil the V-port exhaust through pipe 239 and to control the'rapidity of movement of valve stem |14 in either` direction is accomplished by adjustable means, namely an adjusting screw 243 which supports the plunger 24|. Valve stem 235 is adjustably connected to the solenoid 240 by means of link 244 to obtain the results explained, by means of the adjusting screw 243.

It has been found that in order to obtain the maximum production in`grinding of a camshaft, if each cam is ground for a predetermined number of rotations in grinding engagement with the periphery of the grinding wheel, the cam will be ground to the desired contour and size.

Cycle control In order to obtain the maximum elliciency from the machine, it is desirable to provide a suitable cycle control device which serves, after a cam has been rotated through a predetermined number of rotations in operative grinding contact with the wheel, to actuate the main control valve and to thereby admit fluid under pressure to cylinder chamber to rock the master cams and product cams away from the grinding wheel and the master cam roller respectively, and to admit fluid to the cylinder chamber 59 to move the grinding wheel rearwardly to an inoperative position and to then admit fluid under pressure tothe table traverse cylinder 39 to automatically index the table to present the next cam to be ground into operative relation with the grinding wheel. This is preferably accomplished by means of a cycle control counting device 245 .which is contained within a rectangularly shaped box on the top of the bracket 3|. The counting device comprises a ratchet wheel 246 which is mounted to rotate on a shaft 241. A pawl 248 is carried by a stud 249 on an arm 250 which is connected to move with a lever arm 25| so that the two arms 250 and 25| operate as a bell crank. 'I'he arm 25| is connected by an adjustable link 252, the lower end of which is connected to the stud 82 on the arm 11 which is fixed to the rock bar I8. Each time the rock bar I8 rocks in a counterclockwise direction toward the grinding wheel Iii, the bell crank lever 250, 25| serves to rock the pawl 248 idly over the teeth on the ratchet wheel 246, and when the rock bar I 8 is rocked by the master cams in a clockwise direction (Fig. 3) away from the wheel |6, serving to cause a downward movement of the link 252, and through the bell crank 250, 25| serves to cause the pawl 248 to turn the ratchet wheel 246 a predetermined adjustable amount each time the rock bar moves through its rocking motion. The shaft 241 also carries an adjustable striker arm 253 which is arranged in the path of a lever 254 which serves to rock a support 255 which is pivotally mounted on a stud 256. 'Ihe arm 255 carries a mercury switch 251. When the ratchet wheel 246 has been rotated through a predetermined extent, the striker arm 253 engages the projection 254 and rocks the arm 255 about its supporting pivot 256 and trips the mercury switch 251. The tripping of the vmercury switch serves to close a circuit and to energize the relay 260 which in turn closes a circuit to energize the solenoid 240 to shift the cycle pilot valve 225 and thereby admit fluid under pressure to shift the main control valve |15 toward the right, as viewed in Fig. 2. It will be readily apparent'from the foregoing-that each time the rock bar I8 is osclllated in grinding a cam, the link 252 serves through the bellcrank 250, 25| to oscillate the pawl 248 to cause a movement of the ratchet 246. 'I'he ratchet wheel 246 is limited in its motion in a counterclockwise direction (Fig. 12) by an adjustable stop 26|. The link 252 is provided with adjusting nuts 262 and a spring 263 by means of which the effective length of the link 252 may be adjusted to give the desired action to the pawl 248. The extent of movement of the pawl may be controlled by means j of an adjusting screw 264 which contacts bracket 3|, and is carried by the arm 25| so that between the adjustment of the nuts 262 and the screw 264, the extent of movement of the pawl may be adjusted as desired.

In order that the extent of movement of the pawl 248 may be readily varied to permit adjustment of the number of ratchet teeth picked up at each actuation of the pawl 248, it is desirable to provide a means for readily adjusting the length of the lever arm 25|. The lever arm 25| is provided wlth a slot 265 andthe link 252 is adjustably clamped in the desired location within the slot 265by means of a clamping device 266. By adjusting the position of the clamping device 266l within the slot 265, the effective length of the lever arm 25| may be varied to adjust the Cil trolling the grinding of the next cam blank. This is preferably accomplished by providing a solenoid' 261 which is provided with an upwardly extending rod 268 having a pair of adjustably mounted pins 268 and 218 which are arranged to engage a lever 21I which is an extension of the ratchet pawl '248. A spring 212 surrounds an upper extension of the rod 258 and is interposed between the casing 245 and the nuts 213 which are screw threaded onto the upper end of the rod 268. A spring 214 is connected to a stud 215 on a rotary member or hub 216 which carries the ratchet wheel 246. The other end of the spring 214 is connected to a stud 211 in the upper corner of the control box 245. It will be readily apparent from the foregoing disclosure that when the solenoid 261 is energized, as shown in Figs. 3 and 12, the rod 268 is pulled downwardly against the tension of the spring 212 which serves to rock the lever 21| and the pawl 248 to disengage the pawl 248 from thel ratchet wheel 286. When the pawl disengages the ratchet whee1246,the released tension of the spring 214 serves to rotate the member 216 and the ratchet wheel 246 into its inital position, as illustrated in Figs. 3 and 12, so that the lower surface of the ratchet engages the. adjustable stop 26| so that the mechanism is ready to control the grinding of the next cam blank.

Referring to Figs. 3, 5, and 12, a pivotally mounted safety pawl 218 holds the ratchet wheel 246 as `the pawl 288 rocks toward the grinding wheel I6 to position for feeding the ratchet wheel on its return stroke. It will be noted, therefore, that the pawl 248 rocks idly or to a feeding position when the product cam 26 has the heel or concentric portion of the cam in contact with the grinding wheel I6 and as the cam 28 rotates and thenose or lift of the cam comes in contact with the wheel I8 the ratchet 'wheel 246 is fed, consequently upon completion oi grinding of each cam the cam 28 will leave the wheel I6 when the nose is ln contact with the wheel.

The safety pawl 218 is pivotally mounted on a stud 828 which is fixed toa bracket 338 dependingfrom the casing 245 of the counting or control mechanism. When the ratchet 'wheel is indexed, the safety pawl 218 rides idly Yover the ratchet teeth and prevents the ratchet from turning in the reverse direction. The pawl 248 as above described is carried by a stud 248 which is supported on arm 268 which is formed as one arm of a bell crank lever 2511-251. When the bell crank is rocked in a clockwise direction (Fig:

3), the pawl 248 rides idly over the teeth of the ratchet wheel 246. When the bell crank lever 258-26I is rocked in a clockwise direction, the

pawl 248 engaging the teeth of the ratchet wheel 246 serves to index the ratchet wheel to a new position and the safety pawl serves to hold it in its advanced position. The pawl 248 is provided with a projecting pin. 218 which projects within an elongated slot 38| in the pawl 218. The pin 218 servesA when the arm 21| is rocked in a clockwise direction (Fig. 12) to disengage the pawls 218 and 248 from engagement with the ratchet wheel 248 so as to allovrrv the ratchet wheel to return to its initial position, as shown in Fig. 12.

When the lever 21| rocks to disengage the. pawl 248 from the ratchet wheel 246, a pin 218 carried by the pawl 248 engages the upper surface of an elongated slot in the pawl 218 and serves to lift the pawl 218 from engagement with the ratchet wheel 246 so as to allow the released tension of spring 214 to rotate the ratchet wheel 246 to its starting position. Theelongated slot in pawl 218 allows free movement of pawl 288 `during rocking feeding movement.

The energizing of solenoid 261 is controlled by the control lever 98 which is hereinafter described.

Work rotation The headstock spindle 22 may be rotated by any suitable driving mechanism, such as an electric motor 288 which is connected through a suitable gear mechanism to rotate the work driving center 23V at the desired speed. In the preferred construction, a two speed work drive is provided, such as that shown in the prior patent to :Belden et al. No. 2,022,078 dated November 26, 1935, to which reference may be had for details of disclosure. A manually operable lever 28| serves to move a clutch member 282 into engagement with the clutch members 288 or 284 to rotate the work driverat either a proper speed for .rough grinding or for finish grinding depending on the operation for which the machine .is set. Details of the gear drive between the headstock motor 288 and the center 23 have not been illustrated in detail in the present case, since they are not considered part of thel present invention. For a detailed disclosure of this mechanism, reference Start and trip lever A start and trip lever 288 is pivotally mounted on a stud 281 which is fixed on the lever 2 I 1. The lever 280 is arranged to swing in a substantially horizontal plane and is provided with a projectlng lug 282 which is arranged to engage an extension of pin |22 on the pivotaliy mounted lever |20., When the lever 288 is moved toward the right (Fig. 8) into position 2880i, the lug 282 engages pin 122* and rocks lthe lever 128 about its pivot 12|. This movement serves to move the dog lever II4 toward the grinding wheel I6, as viewed in Fig. 1l, out of the path of the table stop dog II 3. This movement allows the lever H08 to move in a clockwise direction due to the pressure of the spring pressed roller 188 on the arrow head 185 to move the valve stefm 81 toward the left, as viewed in Fig. 2, so as to admit 'fluid from the pipe 83 into valve chamber 84 and out through the pipe 43 into the cylinder chamber 84 to cause the piston 50 and ytable II to move toward the right, as viewed in Figs. 1 and 2. As soon as the dog lever II4 passes spring |25 rocks the lever 128 in a counterclockwisc direction, as viewed in Fig. 11, so that the dog lever H4 lies in the path of the dogs i12. The movement of 'the table II toward the right continues until the dog lever is engaged by the ilrst dog I I2 to position the iirst cam to be ground in operative relation with the grinding wheel i6. This movement rocks the lever 88 and lever 680 to shift the valve stem 81 into the position illusthe table stop dog H8, the

After the start lever has been shifted into position 280e (Fig. 8) to shift the dog lever iid out of the path of.the table stop dog H3 and start the table traverse movement or grinding cycle, the lever 280 is shifted back so dog lever H4 will be fr-ee to contact the first table dog II2 butr not closing the limit switch 288. However, when the table is stopped by `the ilrst dog i l2, the lever 288 is moved the rest of the. way to position 2881 to close limit switch 299 to energize solenoid 240 to operate the cycle pilot valve 225. This serves to move a pin 294 carried by the lever 290 into position 294a out of the path of the surface 295, which serves to allow a. lever 296 to rock about its supporting stud'291 and allows a rod 298 of a limit switch 299 to move upwardly to close the circuit and render the mercury switch 251 effective. Closing the limit switch 299 serves to energize a relay 260'which in turn makes a circuit to energize the solenoid 240 which shifts the cycle pilot valve 225 to the dotted line position, as shown in Fig. 6, so that fluid entering the cycle pilot valve chamber 23| passes outwardly through the pipe 231 to move the main control valve |15 toward the right, as viewed in' Fig. 2, to permit the exhaust of uid from the rock bar cylinder chamber 90 to allow the rock bar to rock in a clockwise direction (Fig. 2) towards the grinding wheel I6 so that the master cam 28 engages the master cam roller 29 and admits fluid under pressure to cause the grinding wheel slide I5 to move toward the work to grind a cam blank. l

The grinding wheel continues its forward feeding movement to grind the cam to the desired size and contour and the wheel then recedes, after which uid is admitted to the wheel feed cylinder chamber 59 to cause a rearward movement of the grinding wheel I6.

A normally open -limit switch 305 is arranged so that its actuating roller 301 engages the lever 98 in the position of the parts illustrated in Fig.

2 and closes the limit switch 305 to energize solenoid 261 to return ratchet wheel 246 to its initial position. When the dog lever I I4 is shifted out of the path of the table stop dog I I3, the lever 98 moves in a clockwise direction into position 98a (Fig. 4) which serves to shift the valve 91 to start the table traverse. At the same time, the lever 98, which engages the roller 301 of the limit switch 305, is rocked in a clockwise direction to break the circuit and thereby deenergize a relay 306 which in turn deenergizes the solenoid 261 to render the ratchet pawls 248 and 218 of the cycle control mechanism 245 operative. The ratchet pawls 248 and 218 remain in engagement with the ratchet wheel 246 during the indexing of the table Il, the lever 98 being in position 98a and the limit switch 305 being open to make the solenoid 261 inactive.

When the work table II reaches the extreme position to the right, a dog 308 on the table II engages the vertical plunger 309 and causes it to move downwardly so as to open the limit switch 299. The opening of limit switch 299 serves to break lthe circuit to renderthe mercury switch 251 inoperative which in turn deenergizes the relay 260, thereby deenergizing the solenoid 240 so that the cycle pilot valve 225 moves downwardly (Fig. 2) due to the released tension of the spring 234. This movement of the cycle pilot valve 225 serves to shift the wheel feed control valve 60 so as to admit fluid under pressure to cause a rearward movement of the grinding wheel I6 and its supporting slide I5. This is preferably accomplished by providing a dog 308 on the table II. 'I'he dog 308 is arranged in the path of a vertical plunger 309 which is connected'to a lever 296 which cooperates with rod 298. The lever 296 is pivotallysupported on a stud' 291 and arranged so that when the dog 308 depresses the plunger 309, the lever 296 swings in a counterclockwise direction to depress the rod 298 of the limit switch 299 which serves to open the switch, thereby rendering the cycle control mechanism inoperative.

The'dog 308 engages the plunger 309 which is depressed. 'I'he table reversing dog 3|8 moves the lever 98 from position 98a to 98h. In this `movement the pin 294 moves from position 294a tion it assumes at the start of the grinding cycle.

When lever 98 swings the lever 3|| to the full line position indicated in Fig. 10 the lever 290 swings into the dot and dash position indicated by an arrow (Fig. 8) to allow dog lever ||4 to clear the dogs I I2 on the return stroke. Table stop dog I| 3 which projects in further, being of the pivot type allowing swinging in one direction counterclockwise (Fig. 4), will let dog lever |I4 pass by, and upon completion of the truing operation will stop the table II for the next grinding cycle. In the last truing pass the lever 98 is in position 98a, though pin 3|4-contacts latch 3|3 to swing lever 3|| to the full line position (Fig. 4) so that dog lever 4 will move by means of spring |25 into further contacting relationship with the table stop dog I|3 at the end of the grinding cycle.

Operation Assuming the table I I to be in its extreme lefthand or loading position, the machine is started into operation by rst pushing an electric control button (not shown) to start the rotation of the grinding wheel I6, then pushing a second button (not shown) to start the rotation of the fluid pressure pump 63. Push button 3I5 is closed to start the rotation of the work driving motor 280. The work piece, such as a camshaft .26, is then loaded in the machine and supported between the headstock center 23 and footstock center 25. 'I'he work drive clutch is then engaged by shifting the lever 28| to engage the movable clutch member 282 with either theY clutch member 283 or 284,

depending upon whether a finish grinding -or a 7 rough grinding speed of the work is desired. The cycle control push button 3| 6 is then closed to render the mercury switch 251 operative so that the machine is then under the control of the cycle counting mechanism 245. The hand lever 290 is then moved toward the right into position 290a (Fig. 8). 'I'his movement serves to rock the lever 290 about its vertical supporting stud 29| so that the lug 292 engaging the pin I22 rocks the lever |20 about its pivot |2I, as viewed in Fig. 11, to move the dog lever I|4 out of the path of the table stop dog II3. This movement allows the released tension of the spring pressed roller |06 to rock the levers 98 and |00 in a clockwise direction,` as viewed in Figs. 2 and` 4, which serves to shift the valve stem 91 toward the left,

. as viewed in Fig. 2, so that fluid under pressure passing through the pipe 93 into the valve chamber 94 passes outwardly through the pipe 43 into the cylinder chamber 44 to move the piston 40 and table toward the right to bring the rst cam on the camshaft 26 into operative grinding relation with. the wheel I6. The longitudinal movement of the table continues until the first dog ||2 engages the dog lever ||4 which serves to rock the lever 98 from the position 98a into position 98, thereby moving the valve stem 91 toward the right, as viewed in Fig. 2, to cut oif fluid from the pipe 43 and thereby stop the movement of the .table II. When the lever 98 returns to the position illustrated in Fig. 2, the limit switch 305 closes, serving to energize a relay 306o which in turn energizes the solenoid 261 towithdraw the pawls 248 and 218 from engagement with the ratchet wheel 246 so as to allow the released tension of the spring 214 to return the ratchet wheel 246 and mercury switch 251 to a starting position ready for the control of kthe next grinding cycle. When lever 290 is shifted toposition 290b at the start of the grinding cycle, the limit switch 299 is closed and the solenoid 240 is energized to shift `the cycle pilot valve 225 to the dotted line position, as viewed in Fig. 6, so as to i admit fluid under pressure from the pipe 230 through the valve 'chamber 23| and through a pipe 231 into the chamber 236 to move the main control valve |15 toward the right, as viewed in Fig. 2. The operator allows the table II to traverse to the first dog I|2 before shifting the lever 290 completely over to close the limit switch 299..v This movement of the main control valve |15 serves to cut off the flow of fluid through the pipe 93 to the table reversing valve 9| and serves to admit thefiow of fluid under pressure through the pipe |32 into a cylinder chamber |33 to move the piston |28 toward the left, as viewed in Figs. 2 and 11, which serves to rock the lever |20 in a clockwise direction and thereby serves to move the dog lever |I4 out of the path of the table dog I2. At the same time fluid under pressure passing through the pipe |32 enters a valve cham- 'ber 3|1 to move the wheel slide control valve toward the left, as viewed in Fig. 2, so that fluid under pressure passing through the pipe 60 enters a valve chamber 65 and passesoutwardly through a pipe 56 into a chamber 5l -to cause the grinding wheel to be fed into the cam being ground. At the same time the main control valve is shifted, as above mentioned, fluid is allowed to exhaust from the cylinder chamber to allow the rock bar I8 to rock so`-that the master cam 28 engages the master cam roller 29. Rotation of the master cam roller in contact with the master cam serves to rock the camshaft to grind a cam blank to a predetermined contour. Each time the rock bar I8 rocks toward and from the grinding wheel, the cycle control counting device 245 is operated, and the link 252 and bell crank 250-25i serve to rock the pawl 248 to turn the ratchet wheel 246 until the striker 253 engages the lever 254 ofthe mercury switch supporting member 255 to rock the mercury switch 251 and thereby break the circuit, which serves to deenergize the relay 260 to break the circuit and deenergize the solenoid 240 which in turn releases the tension of the spring 234 to permit the cycle pilot valve 225 to move into the full line position, as illustrated in Figs. 2 and 6. This movement of the cycle pilot valve 225 allows fluid passing through the pipe 230 to enter the valve chamber 23| and to pass through the pipe 232 into a valve chamber 233 at the right-hand end of lthe main control valve |15 to move the valve toward the left, into the position of parts illustrated in Fig. 2. This movement of the main control valve |15 again opens the passage of fluid through the pipe 93 to valve chamber 96 and allows it to pass out through the pipe it to the cylinder chamber @i0 to again index the pistou' 40 and the table ii iongitudinaily to present the next cam into operative relatioriwith the grinding wheel I6. This cycle of operation is continued until each one of the successive cams on the product camshaft is ground to the desired size and contour. Each time the table II is indexed longitudinally to present a new product cam to the grinding wheel, the master cam roller 29 is indexed longitudinally by an indexing mechanism, not shown in the present application. This feature is not considered part of the present inven- -f tion and consequently has not been illustrated in detail. For reference to the details of the master cam roller indexing mechanism, reference may be had to the above-mentioned patent to Belden and Silven No. 2,022,178 dated November 26, 1935. When the dog lever II4 is moved out of the path of the dog H2, the released tension of the spring-pressed roller |06 serves to rock the levers 98 and |00 in a clockwise direction into the position 98a. V

This movement serves to open the limit switch 305 which in turnserves to deenergize the solenoid 261 and allows the pawls 248 and 218 to engage the ratchet wheel 246 so that upon oscillation of the rock bar I8 the pawl 248 may be oscillated to turn the ratchet wheel 246 after each actuation of the rock bar to control the cycle of grinding on the cam 26. After the cam has rotated through a predetermined number of rotations in contact with the grinding wheel during the grinding operation, the mercury switch 251 is tipped to break the circuit and the breaking of the circuit serves to release the relay 260 to deenergize the solenoid 200 and the released tension of the spring 23d then returns the valve 225 into the position illustrated in Fig. 2. In this position of the valve 225 fluid under pressure from pipe 230 passes through valve chamber 23l and pipe 232 into the chamber 233 at the right-hand end (Fig. 2) of the main control valve H15. This movement of the main control valve serves to allow fluid under pressure to pass through the pipe 93 into the valve chamber 96 and the valve stem 9i having been previously moved toward the left when the dog lever i lli was withdrawn from the table dog El i2 so that fluid under pressure entering the valve chamber 90 passes out through pipe 43 to index the piston 90 and table i i toward the right. This movement continues until the next dog M2 engages the dog lever i90 to again stop the table movement when the next cam is in operative relation with the grinding wheel.

This cycle of events continues until the last cam on the left-hand end of the camshaft to be ground (Fig. l) has been ground, after which the table i i is traversed to a further position toward the right so that the wheel is to the left of the last cam on the shaft. During this movement beyond the last cam on the shaft, the dog 308 engages the plunger 20@ which serves to rock the lever 296 and allows pin'29t to move freely oversurface 295 and the levers 96 and 200 to take position 98h and 290cv.. .The pin 200 holds the limit switch 299 open. This opening of limit switch 29@ serves to deenergize the mercury switch 25H and allow the pawl to drop into operative contact with the ratchety wheel. At the same time, the table reversing dog 360 engages the table pilot valve lever |32 and rocks it in a clockwise direction (Fig. l0), serving to move thel valve H25 toward the left, as viewed in Fig. 2. 4'This movement serves to allow 'ffuid under pressure passing through pipe i4@ 'till tering the reverse valve chamber 320 shifts the valve toward the right, as viewed in Fig. 2, so that the arrow point |05 passes over the high point of the spring-pressed roller |06 and the arrow point serves to hold the reverse valve in a reverse position so that uid under pressure passing through the pipe 93 into the valve chamber 94 then passes out through a pipe 45 into the cylinder chamber 46 of the table operating cylinder 39 to cause the table to move rapidly through an idle stroke toward the left, as viewed in Figs. 1 and 2, with lever 98 in position 98h', as viewed in Fig. 10. This movement serves to return the ta'ble to its initial or starting position. When the table- I I approaches the left-hand end of its movement, a truing dog |31 engages the roller |63 and depresses the same, which serves to shift the truing speed valve |51) toward the right, as viewednin Fig.A 2, so that fluid under pressure exhausting from the table cylinder 39 passes through a V- port |59 to throttle the exhaust thereof and to regulate the speed of movement of the table while the truing tool |41 of the truing apparatus |45 passes across the operative face of the wheel I6. The table continues its traverse toward the left until the truing tool |41 passes across the .face of the wheel, whereupon a depending projection of the truing dog |31 engages the lever |38 to rock it in a counterclockwise direction to move the valve stem |39 toward the right, as viewed in Fig. 2, serving to admit fluid under pressure entering through pipe |40 and valve chamber |4| out through a pipe |42 into a valve chamber |43 at the right-hand end of the table reversing valve 9|. This movement serves to shift the table reversing valve into the position illustrated in Fig. 2, so that the valve is in position ready to start the next grinding cycle after the finish ground camshaft has been removed and replaced with a new camshaft to be ground. When the reverse valve shifts into the position above dei scribed, the table starts its return stroke toward the right to pass the diamond across the face of the wheel a second time and continues this `motion until the dog lever I I4 engages the table stop dog ||3 which stops the table just before the rst cam moves into operative relation with the grinding wheel. The Vmachine is then in a stopped position and the ground camshaft 26 may be readily removed and vreplaced with a fresh camshaft to be ground.

When the grinding wheel I6 is to be trued, it is customary to advance the wheel slide I5 so that a suflicient amount maybe trued to present a new grinding face to obtain best results. This may be accomplished by an adjustably mounted dog on the table which actuates a mechanical feed mechanism connected to feed wheel 52. The details of this mechanism have not been completely illustrated and described inasmuch as this is not part of the present invention. Reference may be had to the above-mentioned Belden and Silven Patent No. 2,022,178 for details of disclosure.

During the truing operation the headstock motor 280 is stopped by means of the adjustably mounted table dog 32| to permit the removal of the finish ground camshaft 26 from the machine during the truing operation. Dog 32| slides over and depresses a rod 322 of a limit switch 323 which breaks the circuit to deenergize a relay 324 which stops the headstock motor 280. Asthe table reciprocates during the-truing operation the table dog 32| slides over the rod 322 and upon completion of the truing operation, the table moves to the table stop dog ||3 at the end of the grinding cycle, dog 32| still maintaining contact with the rod 322. Upon starting of the grinding cycle, the dog 32| will come out of contact with the rod 322 to close the limit switch 323 to start the headstock motor 280 before the first cam 26 comes into operative relationship with the grinding wheel |6.-

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together withy many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth, or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.

We claim:-

1. A grinding machine comprising a rotatable grinding wheel, a transversely movable slide to support said wheel, a longitudinally movable table, means including a rotatable'work supporting spindle .on said table, means including a fluid pressure piston and cylinder to move said slide transversely, means including a fluid pressure piston and cylinder to move said table longitudinally, a control valve arranged to admit fluid under pressure to either of said cylinders, and a cycle control mechanism actuated by and in timed relation with the rotation of the work supporting spindle to actuate said control valve.

2. An automatic cam grinding machine comprising a rotatable grinding wheel, atransversely movable slide to support said wheel, a longitudinally movable table, a rotatable cam shaft support pivotally mounted on said table, means to move said table longitudinally, means to move said wheel slide transversely to grind successive cams to a predetermined size. means including a plurality of master cams and a follower to rock said camshaft support relative to said table and grinding wheel to causea secondary relative transverse movement between the wheel and camshaft support to grind successive cams to a predetermined contour, a cycle control mechanism actuated by and in timed relation with the rocking camshaft support, and means actuated by said cycle control mechanism to automatically separate the grinding wheel and camshaft after the cam has rocked a predetermined number of Atimes toward the wheel axis and to automatically index said table and camshaft longitudinally to position successive cams into operative relation with the grinding wheel.

3.` An automatic cam grinding machine comprising a rotatable grinding wheel, a transversely movable slide to support said wheel, a longitudinally movabletable, a pivotally mounted work support on saidtable, means including a rotatable camshaft supporting spindle thereon, a plurality of master cams rotatably supported on said work support in axial alignment with the camshaft to be ground and integrally attached thereto, a follower roller arranged to be operatively positioned relative to said master cams and cooperating therewith to rock said work support to produce a predetermined contour on the cams being ground, a cycle control mechanism actuated by and in timed relation with the rotation of said master cams, and means actuated by said cycle control mechanism to control the movement of said grinding wheel toward and from the work, the rocking of said work supportaimais and the indexing of said table to present successive cams into operative relation with the grinding wheel, and to return said work table to the initial loading position.

4. An automatic cam` grinding machine comprising a rotatable grinding wheel and a work support for rotatably supporting a camshaft which are movable longitudinally and transversely relative to each other, means to cause a transverse feeding movement of the grinding wheel to grind a cam blank to a predetermined size, means to cause a predetermined transverse movement of the work support toward and from the grinding wheel to generatea predetermined contour on the cam blanks, means to cause an intermittent relative longitudinal indexing movement between the grinding wheel and the work support in one direction to position successive cams in operative relation with the grinding wheel for grinding; means to cause a rapid relative longitudinal traversing movement between the wheel and work in the opposite direction to return the wheel and work; tol the initial position, a truing toolv carried by the work support, and means to cause a further slow relative longitudinal traversing movement between the wheel and work support to pass the truing tool automatically across the wheel face and then stop in a loading position.

5. A hydraulically driven cam grinding machine having a hydraulically moved wheel supsupporting table, a hydraulically controlled, pivotally mounted camshaft support on said table, means including `a cycle control valve to admit uid under pressure to feed the wheel toward and from the camshaft to be ground, means to admit fluidto cause saidtable to be intermittently traversed longitudinally relative to the grinding wheel to position successive cams in operative relation with the grinding wheel, to admit fluid under pressure to a cylinder to cause said pivotally mounted camshaft support to be moved to an inoperative position during the in.

dexing of the table, a control device operated in timed relation with the movement of said camshaft support, and electrically controlled means operated by said control device to actuate said main control valve after a carri has been rotated a predetermined number of rotations in operative lengagement with the grinding wheel.

6. In a cam grinding machine having a pivo ally mounted camshaft support and master cams and a follower to control the rocking movement of said support, a control device including an electric switch, means including a pawl and ratchet mechanism to actuate said switch, means actuated by the rocking movement of said camshaft support to intermittently index said ratchet ,wheel to actuate said switch, and an electrically controlled mechanism operated when said switch is actuated to causeva separation of the master cam follower when the high point of the cam being ground is in engagement with the wheel.

'7. An automatic cam grinding machine comprising a rotatable grinding wheel and a rotatable work support whichl are movable longitudinally and transversely relative to each other to grind the surface cams on an integral camshaft, means including a fluid pressure jpiston and cylinder to cause a relative longitudinal indexing movement between the grinding wheel and the camshaft support to bring successive cams into operative relation with the grinding wheel, means including a fluid pressure piston and cylinder to cause a relative transverse movement between the grinding wheel and camshaft support to grind successive cams to a predetermined size, means including a set of master cams and a follower to cause a relative transverse movement between the grinding wheel and work to grind successive cams to a predetermined contour, means including a fluid pressure piston and cylinder operatively conneted to render said master cams inoperative,

' arranged to actuate said main control valve when said switch is actuated to admit fiuid under pressure to the camshaft support cylinder to separate the master cam from the follower, to admit duid under pressure to cause a transverse separating movement between the grinding wheel and camshaft support, and to admit fluid to said rst cylinder to cause a longitudinal indexing 1movement between the grinding wheel and the camshaft support.

8. A cam grinding machine having ua wheel slide, a work table and a rock bar thereon, 'each porting member, a hydraulically traversed work of which is operated by a separate fluid motor, a main control valve in control oi. said motors, a pilot valvein control of said main controlvalve, and a cycle control mechanism actuated in timed relation with the rocking of said bar to actuate said pilot valve.

9. A cam grinding machine having -a wheel slide, a work table anda rock bar thereon, each of which is operated by a separate iiuid motor, a main control valve in control of said motors, a pilot valve in control of said main control valve, and a cycle control mechanism including a pawl and ratchet actuated in timed relation with the roclzingr of said bar during grinding to actuate the pilot valve.

10. A cam grinding machine having a wheel slide, a work table and a rock bar thereon, each of which is operated by a separate iiuid motor, a main control valve in control of lsaid motors, a pilot valve to actuate said main control valve, an electric solenoid to shift said pilot valve, and a control mechanism including an electric switch actuated in timed relation with the rocking movement of said bar during grinding to energize said solenoid.

11. A cam grinding machine having a wheel slide, a work table and a rock bar thereon, each of which is operated by a separate duid motor, a main control valve in control of all of s aid motors, a pilot valve to actuate said main control valve, a solenoid to actuate said pilot valve, a control mechanism including a pawl and ratchet actuated by movement of said lrock bar, and an electric switch operated thereby to energize said solenoid after a predetermined grinding operation.

12. A cam grinding machine having a wheel slide, a work table and a rock bar thereon, each of which is operated by a separate fluid motor, a wheel spindle reciprocating mechanism, a uid motor incontro). thereof, a main control valve in control of all of said fluid motors, a pilot valve to actuate the main control valve, `electrical means to actuate said pilot valve in timed relaof which is operated by a separate uid motor, a main control valve in control of all of said motors,

a pilot valve to actuate said main control valve,

a solenoid to actuate said pilot valve and a cycle control mechanism including a pawl and ratchet actuated by and in timed relation with the rocking movement of said bar during grinding to control an electric switch so as to energize said solenoid and thereby control the grinding cycle.

14. In a cam grinding machine having a pivotally mounted camshaft support and master cams and a follower to control the rocking movement of the support, a longitudinally movable work table, a transversely movable rotatable grinding Wheel and slide, said rock bar, work table and Wheel slide each being operated by a separate iluid motor, a main control valve to control all of said motors, a pilot valve to control said main control valve, a. cycle control device including a pawl and ratchet actuated electric switch, connections between said rock bar and pawl to actuate the same in timed relation with the rocking of said bar, and electrically controlled mechanism operated by said switch to actuate said pilot valve and thereby control the cycle of operation.

HERBERT A. SILVEN.

CARL G. FLYGARE. 

